The thermoplastic elastomer such as butadiene rubber has an excellent abrasion resistance, flexibility resistance and cold resistance, which is used for various applications in the chemical industry.
The butadiene rubber is polymerized by a solution polymerization method of dissolving 1,3-butadiene monomer in a solvent and then polymerizing it with a catalyst, and commercialized through a drying step after recovering the solvent from the polymerization solution. In the case of preparing the butadiene rubber via the solution polymerization method as above, a large quantity of solvent is used compared to the amount of monomer to be introduced, and thus there was a problem that a large amount of energy is consumed in the process for recovering the solvent and the unreacted monomer after polymerization. Conventionally, the solvent and the unreacted monomer were recovered from the polymerization solution containing the solvent and the unreacted monomer after solution polymerization with a distillation device sequentially connected by two distillation columns, but there was a problem that a large amount of energy is consumed.
Therefore, the process of recovering solvents is required, which is capable of reducing the installation cost of the distillation device and separating high purity compounds.